1. Field of the Invention
This invention relates to polymer blends comprising a polyalkylene terephthalate resin and an organopolysiloxane-polycarbonate block copolymer. The polymer blends have improved mechanical properties based on the impact values greater than the impact values associated with polyalkylene terephthalate resins and heat distortion values at least equal to about the heat distortion temperature of the polyalkylene terephthalate resin component of the blends.
2. Description of the Prior Art
Polyalkylene terephthalate resins are well-known to those skilled in the art including their various associated physical and chemical characteristics as reported in numerous U.S. patents, e.g., U.S. Pat. Nos. 3,047,539, 2,465,319, etc., among others, as well as polyalkylene terephthalate resins described in the Encyclopedia of Polymer Science and Technology, Vol. II, entitled Polyesters, pages 62-128, Interscience Publishers (1969), which disclosures are incorporated herein in their entirety by reference.
Organopolysiloxane-polycarbonate block copolymers are also well-known to those skilled in the art and are described in various U.S. and foreign patent applications including U.S. Pat. No. 3,821,325 (Merritt, Jr. et al.) issued June 28, 1974; U.S. Pat. No. 3,419,635 and U.S. Pat. No. 3,419,634 (both of Vaughn, Jr.) both issued Dec. 31, 1968; U.S. Pat. No. 3,832,419 (Merritt, Jr.) issued Aug. 27, 1974 and U.S. Pat. No. 3,189,662 (Vaughn, Jr.) issued June 15, 1965, among others.
Heretofore, to the best of the knowledge of applicants, blends of polyalkylene terephthalate resins and organopolysiloxane-polycarbonate block copolymers having improved mechanical properties have not been reported by the prior art.